High voltage hybrid station with opposite busbars and shielded cutoff and switching modules for same

ABSTRACT

The invention provides a “hybrid” high voltage multiphase distribution substation having one or more sets of busbars including at least one air-insulated set of busbars ( 10 ), the substation having feeders (A, B, C, D) for air-insulated lines ( 21, 22 ) placed in substantially parallel bays ( 11, 12 ) on either side of the set(s) of busbars ( 10 ) and including metal-clad breaking and switching modules each formed by metal cladding ( 2 ) containing, for each electrical phase passing through a module, breaking and disconnection systems connected to a phase conductor ( 6 ) in an insulating gas, an end disconnection system ( 4 A,  4 B) being placed at each of the two ends ( 13, 14 ) of a module, the substation being characterized in that the feeders are opposite in facing pairs, and in that two opposite feeders (A, B) are electrically interconnected for each electrical phase via a single module ( 1 ) when the break systems ( 3 A,  3 B,  3 C) and the end disconnector systems ( 4 A,  4 B) of said module are closed, said end disconnector systems each being connected to a respective feeder (A, B).

[0001] The invention relates to a high voltage distribution substationthat is hybrid, i.e. comprising both busbars and feeders usingair-insulated technology, and also metal-clad break and switch modulescomprising break and disconnector devices in metal cladding, the modulesbeing used for interconnecting the busbars and the feeders.

[0002] As a preliminary point, it is worth enlarging on the concept of a“hybrid” high voltage substation since it is relatively recent. Airinsulated technology is referred by the initials AIS (for air insulatedsystem) and metal-clad technology by the initials GIS (for gas insulatedsystem). The main desired objective is to reduce the ground areaoccupied by conventional substations (i.e. fully AIS substations), whilenevertheless conserving both the advantages of AIS technology in termsof cost and ease of component replacement, and the advantages of GIStechnology in terms of compactness and behavior relative to pollution.Hybrid substations can be installed as new facilities, but also asextensions to a conventional substation where the space available for anextension is limited.

[0003] A conventional substation having two sets of opposite busbars andfeeders is shown in FIGS. 1, 1a, and 2. That type of substation occupiesa large area on the ground firstly in the direction of the feeder bays(i.e. lengthwise) and secondly in the direction of the busbars (i.e.widthwise) because the feeders need to be opposite in offset bays. Theswitchgear belonging to a particular feeder must be located beneath bothsets of busbars.

[0004] In order specifically to reduce the length of conventionalsubstations, hybrid high voltage substations of the kinds showndiagrammatically in FIGS. 3 and 6 have been developed that usemetal-clad breaking and switching modules for interconnecting thebusbars and the feeders. Such known metal-clad modules are known, inparticular from PCT application WO 00/24100 in which FIGS. 1 and 2 showsingle-phase modules for substations having single and double sets ofbusbars. In that technology, each feeder is associated with its ownmodule, each module serving to connect one or two sets of busbars to afeeder. Thus, two opposite feeders use two modules and are necessarilylocated in two bays that are offset when the substation has more thanone set of busbars. Compared with a conventional substation, that typeof hybrid substation makes it possible to reduce the length of feeders,and thus the length of the substation, but does not make it possible toachieve any significant increase in the number of bays that can beinstalled in a given area. Furthermore, that technology does not make itpossible to interconnect two opposite feeders directly when a moduleneeds to be disconnected from a set of busbars due to an incidentthereon.

[0005] The Applicant has devised a novel type of metal-clad module formaking hybrid substations with facing opposite feeders, enablingmanufacturing costs to be reduced and also making it possible to achievea significant increase in the number of bays that can be installed in agiven area compared with existing substations. A hybrid substation ofthe invention also makes it possible, if necessary, to perform afunction of electrical connection between two opposite feeders.

[0006] To this end, the invention provides a “hybrid” high voltagemultiphase distribution substation having one or more sets of busbarsincluding at least one air-insulated set of busbars, the substationhaving feeders for air-insulated lines placed in substantially parallelbays on either side of the set(s) of busbars and including metal-cladbreaking and switching modules each formed by metal cladding containing,for each electrical phase passing through a module, breaking anddisconnection systems connected to a phase conductor in an insulatinggas, an end disconnection system being placed at each of the two ends ofa module, the substation being characterized in that the feeders areopposite in facing pairs, and in that two opposite feeders areelectrically interconnected for each electrical phase via a singlemodule when the break systems and the end disconnector systems of saidmodule are closed, said end disconnector systems each being connected toa respective feeder.

[0007] In an embodiment of the invention, a single multiphase moduleelectrically interconnects two opposite feeders. For example, for athree-phase substation, two opposite feeders are interconnected by athree-phase module having three phase conductors passing therethroughcontained inside the metal cladding of said module and each connected toa respective overhead bushing at each end of the module.

[0008] In an embodiment of the invention, two opposite feeders of asubstation convey a number n of electrical phases and are interconnectedby n single-phase modules. For example, for a three-phase substation,two opposite feeders are interconnected by three single-phase moduleseach having a single-phase conductor passing therethrough and connectedto an overhead bushing at each end.

[0009] In a preferred embodiment of the invention, the first and secondfeeders form aligned bays that are perpendicular to a set of busbars.For a substation having at least two sets of busbars, the two sets aregenerally parallel to each other and perpendicular to the feeders.

[0010] In an embodiment of the invention, each end disconnector systemin the cladding of a module comprises, for each electrical phase, an enddisconnector leading to an overhead bushing electrically connected to afeeder of the substation, and in which said end disconnectors areconnected in series with two break systems comprising two circuitbreakers themselves disposed on either side of one or two incomingdisconnectors each leading to an overhead bushing electrically connectedto a corresponding busbar of a set of busbars. The embodiment having asingle incoming disconnector is particularly intended for installing themodule in a substation having a single set of busbars where the incomingdisconnector is generally referred to as the busbar disconnector.

[0011] In an embodiment of the invention, the substation has two sets ofbusbars and a breaking and switching module has two incomingdisconnectors directly connected to each other by the phase conductor.The two incoming disconnectors are generally referred to as switchingdisconnectors.

[0012] In an embodiment of the invention, the substation has two sets ofbusbars and a breaking and switching module has two incomingdisconnectors connected to each other by a separation disconnector inseries with the phase conductor.

[0013] The invention also provides a breaking and switching moduleformed by metal cladding containing an insulating gas, and for eachelectrical phase: a first circuit breaker connected to a phase conductorpassing through said module; each of the two ends of said module havingan end disconnector per phase connected to an overhead bushing; anincoming disconnector being located between the circuit breaker and oneof the end disconnectors; the module being characterized in that thecladding contains a second circuit breaker connected in series with thefirst circuit breaker in such a manner that the incoming disconnector issituated between the first and second circuit breakers. This type ofmodule of the invention is intended in particular for hybrid substationshaving a single set of busbars and for H hybrid substations. Theincoming disconnector of a module of the invention is generally referredto as the busbar disconnector. In most applications, it leads to anoverhead bay, but it is also possible to have it lead to a box forsheathed cables or to a metal-clad line without going the ambit of theinvention.

[0014] In an embodiment of the invention, the cladding of a modulecontains for each electrical phase a second incoming disconnector placedbetween the first and second circuit breakers. This embodiment isparticularly intended for installing the module in a substation with twosets of busbars where the two incoming disconnectors are generallyreferred to as switching disconnectors. In a first embodiment of amodule, the two incoming disconnectors are directly interconnected bythe phase conductor. In a second embodiment, a separator disconnector inseries with the phase conductor interconnects the two incomingdisconnectors so as to make it possible to isolate the two symmetricalhalves of the module from each other. The two sets of busbars in asubstation of the invention can be entirely air-insulated (AIS) or itcan comprise a combination of AIS and GIS, with a first set of busbarsin air and a second set in metal cladding.

[0015] In another embodiment of a hybrid substation module of theinvention, in particular intended for a “one-and-a-half breaker”configuration, two feeders and two sets of busbars are interconnected bya module comprising three circuit breakers in series, one circuitbreaker being placed between the two disconnectors which are used asoutgoing disconnectors leading to line feeders. Other substations of the“one-and-a-half breaker” type can be implemented by associating a twocircuit breaker module of the invention with a conventional modulehaving a single circuit breaker.

[0016] Optionally, at least one break or disconnection system for amodule of the invention is placed in a compartment specific theretowithin the cladding of the module, said compartment being isolated inleakproof manner from the adjacent compartments.

[0017] Optionally, a module of the invention has at least one currenttransformer disposed between an end disconnector and an overhead bay,and/or between an incoming disconnector and a circuit breaker.

[0018] The invention, its characteristics, and its advantages aredescribed in greater detail below with reference to the accompanyingfigures.

[0019]FIG. 1 shows a conventional substation with two sets of busbarsand opposite feeders.

[0020]FIG. 1a is a diagram showing the way the feeders of a conventionalsubstation as shown in FIG. 1 are offset.

[0021]FIG. 2 is a perspective view of a conventional substation of thekind shown in FIG. 1.

[0022]FIG. 3 is a perspective view of a prior art hybrid substation withtwo sets of busbars and in which the opposite feeders are in bays whichare offset.

[0023]FIG. 3a is a theoretical electrical circuit diagram for asubstation of the kind shown in FIG. 3.

[0024]FIG. 4 is a perspective view of a hybrid substation of theinvention with two sets of busbars and a three-phase version of amodule.

[0025]FIG. 4a is a theoretical electrical circuit diagram of asubstation of the kind shown in FIG. 4.

[0026]FIG. 5 is a fragmentary view of a variant module for a hybridsubstation with two sets of busbars as shown in FIG. 4.

[0027]FIG. 5a is a theoretical electrical circuit diagram of asubstation using a module of the kind shown in FIG. 5.

[0028]FIG. 5b is a perspective view of a hybrid substation of theinvention with two sets of busbars equivalent to that shown in FIG. 4,but with three individual modules each in a single-phase version.

[0029]FIG. 6 is a perspective view of a prior art hybrid substation witha single set of busbars and in which opposite feeders are in bays thatare offset.

[0030]FIG. 6a is a theoretical electrical circuit diagram of asubstation as shown in FIG. 6.

[0031]FIG. 6b is a perspective view of a conventional hybrid substationwith a single set of busbars equivalent to that shown in FIG. 6, andwith three individual modules each in the single-phase version.

[0032]FIG. 7 is a perspective view of a hybrid substation of theinvention with a single set of busbars.

[0033]FIG. 7a is a theoretical electrical circuit diagram of asubstation of the kind shown in FIG. 7.

[0034]FIG. 8 is a perspective view of a hybrid substation of theinvention for a so-called H configuration.

[0035]FIG. 8a is a theoretical electrical circuit diagram of an H hybridsubstation of the invention.

[0036]FIG. 9 is a perspective view of a conventional hybrid substationusing a “one-and-a-half breaker” configuration.

[0037]FIG. 10 is a perspective view of a hybrid substation of theinvention for a “one-and-a-half breaker” configuration.

[0038]FIG. 10a is a theoretical electrical circuit diagram of a“one-and-a-half breaker” type hybrid substation of the invention.

[0039]FIG. 11 is a perspective view of a variant module for a“one-and-a-half breaker” type hybrid substation of the kind shown inFIG. 10.

[0040]FIG. 12 is a perspective view of a hybrid substation of theinvention in a “one-and-a-half breaker” configuration using a module ofthe invention in association with a conventional module.

[0041]FIG. 13 is a perspective view of a hybrid substation of theinvention having two sets of busbars: an AIS set and a GIS set.

[0042]FIG. 14 shows one electrical phase of a variant module of theinvention for a substation with two sets of busbars in which theswitching disconnectors are placed in parallel.

[0043] In FIG. 1, a conventional AIS substation is fitted with two setsof busbars 10 and two switching disconnectors 18 for each electricalphase in a bay 11 or 12, each switching disconnector being capable ofconnecting one phase of a feeder A or B to the same phase of a set ofbusbars 10 as conveyed by a particular busbar 9. A feeder typicallycomprises a series connection of AIS gear such as a circuit breaker 15,a current transformer 16, and a line grounding disconnector 17. Theswitching disconnectors 18 of a given feeder must be located beneathboth sets of busbars 10, as can also be seen in FIG. 2, and they occupya ground area approximately equal to the combined width of both sets ofbusbars. This implies that two opposite feeders A and B cannot beexactly side by side and thus that the bays 11 and 12 that they occupymust be offset in their length direction, i.e. transversely to thedirection in which the busbars extend. A feeder A or B terminates in anelectricity line 21 or 22 that is in line with its bay 11 or 12, thelines generally being supported by gantries 23 and 24 astride thefeeders.

[0044]FIG. 1a shows the lengthwise offset of the bays 11 and 12 foropposite feeders A, B, C, and D.

[0045] In FIG. 2, the perspective view of a conventional substationshows more clearly how the bays 11 and 12 are offset lengthwise.

[0046]FIG. 3 is a diagrammatic perspective view of a prior art hybridsubstation with two sets of busbars in which each feeder A or B isassociated with a respective module 7A specific thereto. These modules7A are known, in particular from PCT application WO 00/24100, and theyare shown in their three-phase version in the figure, with three phaseconductors 6 being contained within the metal cladding 8 of one module.To simplify the diagram, only one conductor 6 is drawn. The cladding 8contains one circuit breaker 3 and three disconnectors 4 per phase witheach disconnector leading to an overhead bushing 5. A first disconnectorknown as a line disconnector is connected to an electricity line 21 or22 of a feeder A or B, while the other two disconnectors known asswitching disconnectors are connected to respective busbars 9 of twosets of busbars 10.

[0047] Each module serves to connect one or the other of the two sets ofbusbars 10 to a feeder. Thus, two opposite feeders such as A and B or Cand D use two modules that are disposed in two bays 11 and 12 that arenecessarily offset lengthwise. This configuration having two modules fortwo opposite feeders makes it possible in particular to continue to feeda feeder even if the module belonging to the opposite feeder is out ofservice. Nevertheless, it does not make it possible to interconnect twoopposite feeders directly in the event of it being necessary todisconnect a module from a set of busbars due to an incident thereon.

[0048]FIG. 3a is a circuit diagram of the hybrid substation shown inFIG. 3. The feeders B and D are assumed in this case to feed powertransformers on lines 22. The line disconnectors are closed and are notshown, while the switching disconnectors are indeed shown between thetwo sets of busbars 10. It can be seen that two opposite feeders such asA and B or C and D cannot be directly interconnected. Nevertheless, byclosing the switching disconnectors in an appropriate configuration, itis possible to feed one or the other of the two sets of busbars 10 by alive feeder A or C so as to feed the feeders B or D on the other side ofthe sets of busbars. Naturally such an indirect connection betweenopposite feeders cannot be established when the sets of busbars areunavailable.

[0049]FIG. 4 is a perspective view of a hybrid substation of theinvention with two sets of busbars, and with a single three-phase module1 interconnecting two opposite feeders such as A and B or C and D. Twoopposite feeders form bays 11 and 12 that are in alignment,substantially perpendicularly to the two sets of busbars 10. The bays ofsuccessive opposite feeders are substantially parallel and facing, andthey thus occupy an area whose depth dimension is approximately halfthat required by the same number of feeders in a conventional hybridsubstation as shown in FIG. 3. As in a conventional AIS substation or aconventional hybrid substation, a feeder A or B is connected to anelectricity line 21 or 22 in line with its own bay 11 or 12, and thelines 21 and 22 are carried in general by gantries 23 and 24 placedastride the feeders. Because the opposite feeders A and B are facing,the hybrid substation of the invention has lines 21 and 22 in alignment.

[0050] The module 1 shown has three phase conductors 6 contained inmetal cladding 2. To simplify the drawing, only one conductor 6 is shownas in FIG. 3. As for conventional hybrid substation modules, a modulefor a hybrid substation of the invention is essentially formed bygenerally tubular metal cladding having respective end disconnectors 4Aand 4B at opposite ends 13 and 14 leading via corresponding overheadbushings 5A or 5B that convey electricity in and out of the module tooverhead lines.

[0051] A feature of the invention is that the overhead bushings 5A or 5Bat each of the ends of a module are all connected to a line 21 or 22 ofopposite feeders such as A and B, e.g. by means of cables.

[0052] In the substation with two sets of busbars shown in FIG. 4, amodule 1 has, per phase, two circuit breakers 3A and 3B connected inseries by a phase conductor 6, and also two incoming disconnectors 4M,also known as switching disconnectors. The two switching disconnectors4M make it possible to switch the load of one and/or the other of thetwo sets of busbars to one and/or the other of the two opposite feeders,and vice versa. Each switching disconnector is connected to a branchfrom the phase conductor 6 situated between the two circuit breakers 3Aand 3B, and it is connected to a corresponding set of busbars 10 viaoverhead bushings 5M.

[0053] The circuit diagram of the substation with two sets of busbarsprovides an advantage in terms of supply availability over the circuitwith only one set of busbars. In the event of one of the sets of busbarsbeing unavailable, the switching disconnector 4M connected thereto isleft open while its neighbor connected to the available set of busbarsis closed. One and/or the other of the opposite feeders can then againbe fed via the available set of busbars.

[0054] In a preferred embodiment, each switching disconnector iscontained in a compartment that is isolated in leakproof manner from theother compartments within the cladding of the module, and the twoadjacent switching disconnectors 4M are separated from each other by aleakproof partition constituted in conventional manner by a cone ofelectrically insulating material. This embodiment presents the advantageof conserving the availability of one set of busbars in the event of afault in the switching disconnector compartment that is connected to theother set of busbars. Putting switching disconnectors into compartmentsmakes it possible to avoid a fault on one disconnector in a firstcompartment propagating to the other disconnector situated in anadjacent second compartment that is isolated therefrom. The voltagerating of the open switching disconnector situated in the goodcompartment is therefore unaffected, and the set of busbars connected tosaid second compartment can thus be kept live without requiring thecables connecting it to the module to be disconnected. Only the set ofbusbars connected to the damaged first compartment needs to be taken outof service.

[0055] In addition, in a hybrid substation of the invention operating ina degraded mode can feed a feeder from the line of the opposite feedereven when both sets of busbars are unavailable. The module of theinvention makes it possible to establish an electrical connectionbetween two opposite feeders by closing the two circuit breakers 3A and3B and the two end disconnectors 4A and 4B.

[0056]FIG. 4a is a theoretical embodiment circuit diagram of thesubstation shown in FIG. 4. As in FIG. 3a, the line disconnectors areassumed to be closed and only the switching disconnectors are shown. Itcan clearly be seen that two opposite lines can be directlyinterconnected phase to phase via the phase conductors of a module, byclosing the circuit breakers and the line disconnectors of the module.Compared with FIG. 3a, it is clear that the opposite feeders occupy anarea that is reduced by about half.

[0057]FIG. 5 is a diagram of a variant of the module 1 of FIG. 4 inwhich a separating disconnector 4S is connected in series in the phaseconductor 6 for each of the electrical phases interconnecting the twoswitching disconnectors 4M. Opening the separation disconnector 4Senables each feeder to be switched to the set of busbars on its own sideindependently of the opposite feeder. Furthermore, maintenance can beperformed on one-half of the module, e.g. on the circuit breaker 3B orthe disconnector 4B while keeping the other half of the module (circuitbreaker 3A and disconnector 4A) in operation, providing a temporary orpermanent grounding device (not shown in the Figure) is provided.Advantageously, the switching disconnectors can be compartmented to makeit possible in the event of a fault in one compartment to empty thatcompartment of the dielectric gas it contains and to keep the separationdisconnector open in its isolated compartment without interfering withthe operation of the gear situated in the good half of the module.

[0058] The variant with a separation disconnector thus providesincreased operating flexibility. It can be observed that operatingflexibility is not always total, unlike the conventional substationshown in FIG. 3, since each feeder cannot be switched independently tothe set of busbars on the opposite side.

[0059]FIG. 5a is a theoretical electrical circuit diagram similar tothat of the substation shown in FIG. 4 but further including aseparation disconnector in each phase in a module 1, as shown in FIG. 5.When the separation disconnectors are open, the substation operates astwo symmetrical independent substations.

[0060]FIG. 5b, is a perspective view of a hybrid substation of theinvention with two sets of busbars and with three individual modules 1each constituted by a single-phase version for interconnecting twoopposite feeders such as A and B or C and D. This substation isfunctionally equivalent to that shown in FIG. 4 and it providesadvantages in terms of fault isolation and maintenance. Nevertheless,the ground area occupied along the direction in which the busbars extendcan be slightly greater than that occupied by a three-phase modulebecause of the volume occupied by each individual module.

[0061]FIG. 6 is a perspective view of a prior art hybrid substation witha single set of busbars in which opposite feeders A and B occupy bays 11and 12 that are slightly offset. This substation makes use of onethree-phase module per feeder which comprises, for each phase, a circuitbreaker 3 connected at each end of the module to a disconnector 4. Themodules of the opposite feeders are located in this case in bays thatare offset, but it is possible to place the bays in line, as shown inFIG. 6b.

[0062]FIG. 6a is a theoretical electrical circuit diagram of thesubstation with a single set of busbars shown in FIG. 6, in which theopposite feeders A and B are offset. It is nevertheless possible forconventional hybrid substations with a single set of busbars to placethe modules for opposite feeders in line.

[0063]FIG. 6b is a perspective view of a conventional hybrid substationwith a single set of busbars equivalent to that shown in FIG. 6 butusing three individual single-phase modules for each feeder. In thiscase, the modules of the opposite feeders are disposed in line, with thebusbar disconnectors of two opposite modules being allocated to the samephase and being connected via cables to a busbar 9 corresponding to saidphase, the cables being connected to the busbar at a common connectionpoint 25. That type of substation does not enable two feeders to bedirectly interconnected in the event of the set of busbars beingunavailable unless the cables connected to the common connection point25 are disconnected and the opposite busbar disconnectors are themselvesinterconnected, which involves a difficult intervention.

[0064]FIG. 7 is a perspective view of a hybrid substation of theinvention with a single set of busbars and in which two opposite feedersA and B are interconnected via a single three-phase module 1 and formbays 11 and 12 that are in alignment. Like a substation with two sets ofbusbars, the module 1 comprises, per phase, two circuit breakers 3A and3B in series located between two end disconnectors 4A and 4B eachconnected to a feeder A or B. But because there is only one set ofbusbars 10, this module 1 has only one incoming disconnector 4M perphase which is also referred to as a busbar disconnector, serving toconnect the set of busbars 10 to the phase conductors 6 at a pointbetween the two circuit breakers. When the busbar disconnector 4M isopen, it is possible to interconnect two opposite feeders directly inthe event of the set of busbars being unavailable. The theoreticalelectrical circuit diagram for this substation is given in FIG. 7a.

[0065]FIG. 8 is a perspective view of a hybrid substation of theinvention in a so-called H configuration and a conventional circuitdiagram for the H configuration is given in FIG. 8a. The modules 1 usedin this H substation, and the disposition of the opposite feeders suchas A and B or C and D are similar to the configuration for a hybridsubstation of the invention having a single set of busbars. The incomingdisconnectors 4M or busbar disconnectors of two modules side by side areinterconnected by cables of the set of busbars 20, which cables can bemanually disconnected from the overhead bushings 5M supporting them.When all of the cables constituting the set of busbars 20 are connected,as shown in dotted lines in the Figure, the electrical connection isequivalent to that of a single set of busbars. The H configurationamounts to concentrating on two opposite pairs of feeders in thesubstation, with each pair being connected in this case by means of amodule 1 to the cables of the set of busbars 20 extending between theincoming disconnectors 4M of the two modules. The resulting unit isH-shaped, as can be seen in FIG. 8a.

[0066] In conventional manner, a line L1 or L2 of an H substation isalways associated with a power transformer such as T1 or T2. Theincoming disconnectors 4M are open in normal operation. If a faultoccurs, for example, on the line L1, then the circuit breaker 3A and thedisconnector 4A at the end of the module connected to L1 are opened soas to isolate the upstream and downstream portions of the line. Thecircuit breaker 3B and the disconnector 4B are closed downstream, andthe incoming disconnectors 4M are also closed so that the transformer T1becomes fed by the line L2 at the same time as it feeds the transformerT2. H substations can be operated in other known ways that are notdescribed in the present specification. The invention naturally does notapply to the H configuration per se, but to an H-configuration hybridsubstation using a module 1 of the invention.

[0067]FIG. 9 is a perspective view of a conventional hybrid substationin a “one-and-a-half breaker” configuration. Two line feeders L1 and L2and two sets of busbars 10 are interconnected by three conventionalmetal-clad modules 7B placed in alignment and electrically connected inseries, each module 7B being constituted by a circuit breaker 3contained in metal cladding and having a disconnector 4 at each end andfor each electrical phase which is connected to an overhead bushing. Twoadjacent modules are connected in series by cables interconnecting theiroverhead bushings and also connected to a feeder for line L1 or L2. Theprinciple on which a “one-and-a-half breaker” substation operates can besummarized as follows:

[0068] In normal operation all of the circuit breakers are closed.

[0069] In the event of a fault on one set of busbars, that set ofbusbars can be isolated without losing feed to the line feeders, feedbeing maintained by the good set of busbars, and electricity flowing viatwo of the three circuit breakers.

[0070]FIG. 10 is a perspective view of a hybrid substation of theinvention in a “one-and-a-half breaker” configuration using a singlebreaking and switching module 1 for connecting a set of busbars 10 totwo line feeders L1 and L2. For each electrical phase, the module 1 hasthree circuit breakers 3A, 3B, and 3C connected in series by a phaseconductor 6. Two incoming disconnectors 4M are connected betweenrespective pairs of adjacent circuit breakers and are used in this“one-and-a-half breaker” configuration as outgoing disconnectors leadingto the line feeders L1 and L2.

[0071]FIG. 10a is a theoretical electrical theoretical circuit diagramfor a “one-and-a-half breaker” substation as shown in FIG. 10.

[0072] In FIG. 11, the module 1 shown in FIG. 10 is associated with twoseries-connected disconnectors 4S for each phase in the phase conductor6 so as to enable each circuit breaker 3A, 3B, or 3C to be isolated fromits neighbors by opening one or more disconnectors 4S.

[0073] This makes it possible to provide a hybrid substation of theinvention in a “one-and-a-half breaker” configuration by using atwo-circuit breaker module 1 of the invention associated with aconventional single-circuit breaker module 7B. The module 1 is of thetype used in a hybrid substation of the invention with a single set ofbusbars, the incoming disconnector 4M being connected to a line feederof any kind (air-insulated, metal-clad, sheathed cable, etc.).

[0074]FIG. 12 is perspective view of such a hybrid substation with amodule 1 whose incoming disconnector 4M constitutes a disconnectionsystem connected to underground line feeder L2. This disconnector system4M is constituted, for each phase, by two adjacent disconnectorsconnected in series with the phase conductor 6 and co-operatingtherewith to form a T-branch leading to a portion 27 that projects fromthe metal cladding 2. This projecting portion 27 is designed to enablephase conductor 6 to be connected to a cable 28 which is insulated bymeans of a sheath, it being possible to install a cable box outside thecladding in line with said projecting portion. One end disconnector 4Aof the module 1 is connected to a first set of busbars 10 and the otherend disconnector 4B is connected to a line feeder L1 and to a firstdisconnector of a conventional module 7B whose second disconnector isconnected to a second set of busbars 10.

[0075] The modules used in a hybrid substation of the invention canpresent various types of connection to the disconnectors, depending onthe types of busbar and feeder used in the substation. The hybridsubstation shown in FIG. 4 has two sets of air-insulated busbars 10 andthe incoming disconnectors 4M thus lead to overhead bushings 5M. Ahybrid substation of the invention with two sets of busbars can also beimplemented in combined AIS/GIS manner having a first set of busbars inair and a second set of busbars in metal cladding, in which case one ofthe two incoming disconnectors 4M leads to a connection with the metalcladding of a metal-clad set of busbars.

[0076]FIG. 13 shows one phase of such a substation using combined AISand GIS on two sets of busbars together with the single-phase version ofthe gear, a single-phase module 1 interconnecting two opposite feederssuch as A and B or C and D for each phase. The cladding 2 of a module isconnected via an incoming disconnector 4M to the cladding 30 containingone of the busbars 29 of a set of metal-clad busbars. The volume of thecladding 30 can communicate with the cladding 2 or it can be isolatedtherefrom by a leakproof partition at one end of the incomingdisconnector 4M.

[0077] The modules used in a hybrid substation of the invention with twosets of busbars are shown in the preceding figures with two switchingdisconnectors 4M each constituted by a single disconnector element. Theinvention also covers a variant embodiment of the module in which eachswitching disconnector 4M comprises a disconnection system constitutedby two disconnector elements connected in series with the phaseconductor inside the cladding of a module and forming a T-branchconnection to the inlet of the incoming disconnector. This configurationapplies firstly to an air-insulated substation having two sets ofbusbars, but it can also be applied to two sets of combined AIS and GISbusbars providing a T-branch is arranged to lead to a set of metal-cladbusbars.

[0078]FIG. 14 shows one phase of a single-phase version of such anembodiment for an air-insulated substation with two sets of busbars inwhich each switching disconnector 4M is constituted by two disconnectorelements 4MA and 4MB forming a T-branch, with the two branches beingconnected in parallel in the module 1 and each leading to an overheadbushing 5M connecting the module to the corresponding phase of one ofthe two sets of busbars. This configuration using parallel switchingdisconnectors provides total operating flexibility like that of aconventional hybrid substation as shown in FIG. 3 since each feeder canbe switched independently to one or the other of the two sets ofbusbars. In comparison, substations of the invention as shown in FIGS. 4or 5 do not provide this total flexibility.

1/ A “hybrid” high voltage multiphase distribution substation having oneor more sets of busbars including at least one air-insulated set ofbusbars (10), the substation having feeders (A, B, C, D) forair-insulated lines (21, 22) placed in substantially parallel bays (11,12) on either side of the set(s) of busbars (10) and includingmetal-clad breaking and switching modules each formed by metal cladding(2) containing, for each electrical phase passing through a module,breaking and disconnection systems connected to a phase conductor (6) inan insulating gas, an end disconnection system (4A, 4B) being placed ateach of the two ends (13, 14) of a module, the substation beingcharacterized in that the feeders are opposite in facing pairs, and inthat two opposite feeders (A, B) are electrically interconnected foreach electrical phase via a single module (1) when the break systems(3A, 3B, 3C) and the end disconnector systems (4A, 4B) of said moduleare closed, said end disconnector systems each being connected to arespective feeder (A, B). 2/ A multiphase distribution substationaccording to claim 1, in which a single multiphase module (1)electrically interconnects two opposite feeders (A, B). 3/ A multiphasedistribution substation according to claim 1, conveying a number n ofelectrical phases, in which two opposite feeders (A, B) areinterconnected by n single-phase modules (1). 4/ A substation accordingto any one of claims 1 to 3, in which the first (A, C) and second (B, D)feeders form aligned bays (11, 12) that are perpendicular to a set ofbusbars (10). 5/ A substation according to any one of claims 1 to 4, inwhich each end disconnector system in the cladding (2) of a module (1)comprises, for each electrical phase, an end disconnector (4A, 4B)leading to an overhead bushing (5A, 5B) electrically connected to afeeder (A, B) of the substation, and in which said end disconnectors(4A, 4B) are connected in series with two break systems comprising twocircuit breakers (3A, 3B) themselves disposed on either side of one ortwo incoming disconnectors (4M) each leading to an overhead bushing (5M)electrically connected to a corresponding busbar (9) of a set of busbars(10). 6/ A substation according to claim 5, in which the substation hastwo sets of busbars (10) and in which a breaking and switching module(1) has two incoming disconnectors (4M) directly connected to each otherby the phase conductor (6). 7/ A substation according to claim 5, inwhich the substation has two sets of busbars (10) and in which abreaking and switching module (1) has two incoming disconnectors (4M)connected to each other by a separation disconnector (4S) in series withthe phase conductor (6). 8/ A breaking and switching module formed bymetal cladding (2) containing an insulating gas, and for each electricalphase: a first circuit breaker (3A) connected to a phase conductor (6)passing through said module; each of the two ends (13, 14) of saidmodule having an end disconnector (4A, 4B) per phase connected to anoverhead bushing (5A, 5B); an incoming disconnector (4M) being locatedbetween the circuit breaker (3A) and one of the end disconnectors; themodule being characterized in that the cladding (2) contains a secondcircuit breaker (3B) connected in series with the first circuit breaker(3A) in such a manner that the incoming disconnector (4M) is situatedbetween the first and second circuit breakers (3A, 3B). 9/ A moduleaccording to claim 8, in which the incoming disconnector (4M) isconnected to an overhead bushing (5M). 10/ A module according to claim8, in which the incoming disconnector (4M) comprises a disconnectionsystem constituted for each phase, by two adjacent disconnectorsconnected in series with the phase conductor (6) and forming a T-branchtherewith leading to a projecting portion (27) of the cladding (2), andin which the projecting portion is designed to connect each phaseconductor (6) to a cable (28) that is insulated by a sheath outside thecladding. 11/ A module according to claim 9, in which the cladding (2)contains, for each electrical phase, a second incoming disconnector (4M)disposed between the first and second circuit breakers (3A, 3B). 12/ Amodule according to claim 11, in which the two incoming disconnectors(4M) are directly interconnected by the phase conductor (6). 13/ Amodule according to claim 11, in which a separation disconnector (4S) inseries with the phase conductor (6) interconnects the two incomingdisconnectors (4M). 14/ A module according to claim 11, in which eachincoming disconnector (4M) is constituted by a disconnection systemcomprising two disconnector elements (4MA, 4MB) connected in series withthe phase conductor (6) inside the cladding of the module and forming aT-branch at the inlet of said disconnection system. 15/ A moduleaccording to any one of claims 11 to 14, in which the incomingdisconnector (4M) leads outside the cladding (2) of the module to metalcladding (30) containing at least one phase conductor (29) in aninsulating gas. 16/ A module according to claim 12, in which a thirdcircuit breaker (3C) is placed between the two incoming disconnectors(4M) in series with the first and second circuit breakers (3A, 3B). 17/A module according to claim 16, in which the disconnectors (4S) inseries with the phase conductor (6) make it possible to isolate each ofthe circuit breakers (3A, 3B, 3C) electrically from its neighbors. 18/ Amodule according to any one of claims 8 to 17, in which at least onecircuit breaker or disconnector is placed in a compartment specificthereto inside the cladding (2) of the module, said compartment beingisolated in leakproof manner from the adjacent compartments. 19/ Amodule according to any one of claims 8 to 18, including at least onecurrent transformer (19) disposed between an end disconnector (4A, 4B)and an overhead bushing (5A, 5B), or between an incoming disconnectorand a circuit breaker. 20/ A “hybrid” high voltage multiphasedistribution substation of the one-and-a-half breaker type, thesubstation comprising two sets of air-insulated busbars (10) and twofeeders for lines (L1, L2) at least one of which is air-insulated, thesubstation including metal-clad breaking and switching modules (1, 7B)each formed by metal cladding (2, 8) containing, for each electricalphase passing through a module, breaking and disconnection systemsconnected to one phase conductor (6) in an insulating gas, an enddisconnection system (4A, 4B) being placed at each of the two ends (13,14) of a module, the substation being characterized in that at least oneof the sets of busbars (10) is capable of feeding both line feeders viaa single breaking and switching module (1) as defined in any one ofclaims 9, 10, 16, and
 17. 21/ A “hybrid” high voltage multiphasedistribution substation of the H-type comprising opposite pairs ofair-insulated feeders (A and B, C and D) each connected to anelectricity line (L1, L2), the substation being characterized in thatthe opposite feeders (A and B, C and D) of each line are electricallyinterconnected by a single module (1) as defined in claim 8, and in thatthe overhead bushings (5M) connected to an incoming disconnector (4M) ofa module (1) can be electrically connected phase by phase tocorresponding overhead bushings situated on the adjacent modules.